``Big US cities could be squeezed by unfunded public pensions as they and counties face a $574 billion funding gap, a study to be released on Tuesday shows... Local governments use unique accounting methods that many, such as Mr Rauh, believe understate obligations. Based on his estimates, which use US Treasuries as the benchmark, each household already owes an average of $14,165 to current and former municipal public employees in the 50 cities and counties studied.''